The present invention relates to a safety seat belt locking device for vehicles, where said locking device is in the primary ignition circuit. This device is particularly suitable for guaranteeing the user better security after a collision than with known safety seat belt locking devices.
The primary object of safety seat belts is to protect a car passenger from being thrown against the windshield of the car in case of a collision or abrupt braking. Generally, belts, in particular three-point-belts, have been well-received by the majority of drivers, and in several countries they are compulsory. The locking part of those belts is generally fixed to the floor of the car or near the bottom on a flexible support.
In some cars the lock is part of an electric circuit in such a way that a signal lamp blinks or the starter cannot be actuated if the belt is not strapped on.
On the other hand, there are situations when a safety seat belt might be disadvantageous or even dangerous. After a collision or similar emergency, it may happen that a passenger cannot free himself from the belt, or that rescuers may encounter great difficulties in freeing such persons from the belts. Moreover, there is often the danger of fire following a collision since the ignition cannot always be turned off in such situations.
U.S. Pat. No. 3,311,188 refers to an automatic opening seat belt fastener which opens when the car tilts at a certain angle, wherein said opening is caused by a mercury switch which closes a circuit, thus activating a coil for releasing the tongue portion of the latching mechanism. Afterwards the circuit is interrupted again. However, this system has some disadvantages. It only works if the position of the automobile exceeds a certain angle of tilt. That is it is, only responsive in those collisions when the automobile tilts over. Further, in order to open the latching mechanism a coil has to be activated, so it will not work automatically, if for some reason the electrical circuit is damaged.
U.S. Pat. No. 3,215,220 relates to a safety seat belt release and ignition cutoff system with which, on the one hand, the buckle device can be opened electrically by actuating a switch and, on the other hand, the circuit can be interrupted by manually opening the buckle device. In case of a collision, the ignition circuit is interrupted automatically. This system also has some disadvantages in that the automatic interruption of the circuit depends on the direction of the impact and it is not meant to open the buckle automatically in case of a collision.